With the constant evolution of wireless communications technologies and standards, mobile packet services have been tremendously developed, the data throughput capability of a single User Equipment (referred to as UE) is constantly upgrading. Take the Long Term Evolution (referred to as LTE) system for example, a maximum downlink rate of 100 Mbps data transmission is supported within a 20M bandwidth, and the data transmission rate has been increased, even up to 1 Gbps in the subsequent LTE Advanced system.
The inflatable growth of UE data services makes the related network resources gradually powerless, especially in the case that the new generation of communication technologies (such as, the third-generation mobile communication technology (3G), Long Term Evolution (LTE)) has not yet been extensively networking, and what followed is that the user rate and traffic requirements cannot be met, and the user experience is degraded. The operators must consider how to prevent and change this situation; on the one hand, the promotion and network deployment of new technologies should be accelerated; on the other hand, it is desirable to rapidly improve the network performance by enhancing the related networks and technologies. As well known, except of the wireless network technology provided in the Third Generation Partnership Project (referred to as 3GPP), the current widely applied Wireless Local Area Network (referred to as WLAN), particularly the wireless local area network based on the IEEE802.11 standard, has been widely used in hotspot coverage in homes, enterprises and even the Internet. Wherein, the technical specifications proposed by the Wi-Fi Alliance are applied most widely, therefore in practice the WIFI network is often equated to the WLAN network based on the IEEE 802.11 standard, and in the case of no confusion, the WIFI module is also adopted in the following to describe the wireless transceiver and processing module supporting the WLAN in network nodes.
In this context, some operators and companies have proposed to integrate the WLAN with the relevant 3GPP access network to achieve joint transmission, and to use the WLAN network to achieve the purposes of balancing offload and improving network performance of the relevant 3GPP access network. At present the 3GPP has now developed protocol for 3GPP access network and WLAN Interworking, as shown in FIG. 1, the current 3GPP Interworking WLAN architecture allows the WLAN network using the Authentication Authorization Accounting (referred to as AAA) server in the 3GPP access network for unified authentication and authorization, and can multiplex the packet data network gateway in the relevant 3GPP access network as the packet data gateway in the WLAN network, while also can achieve a unified accounting and charging of two networks, so as to reach a loose coupling of the two networks.
But the current Interworking architecture still has some shortcomings, for example, the current Interworking is triggered by the UE, and the 3GPP network side has no control over the target access network, although the Access Network Discovery Support Function (referred to as ANDSF) at the core network side will give some strategic rules, but these rules are relatively static, the 3GPP network side lost the control on the UE selecting an access network, which may result in that the access network selected by the UE cannot meet the UE's QoS (Quality of Service) requirement, or result in that the UE performs frequent handover between the 3GPP access network and the WLAN access network, thus affecting the user experience and also adding unnecessary burden on the network.